Zoisite, first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH).
Zinkenite is a steel-gray metallic sulfosalt mineral composed of lead antimony sulfide Pb9Sb22S42. Zinkenite occurs as acicular needle-like crystals.
Zirkelite is an oxide mineral with the chemical formula (Ca,Th,Ce)Zr(Ti,Nb)2O7. It occurs as well-formed fine sized isometric crystals. It is a black, brown or yellow mineral with a hardness of 5.5 and a specific gravity of 4.7.
Samarskite is a radioactive rare earth mineral series which includes samarskite-(Y), with the chemical formula (YFe3+Fe2+U,Th,Ca)2(Nb,Ta)2O8 and samarskite-(Yb), with the chemical formula (YbFe3+)2(Nb,Ta)2O8. The formula for samarskite-(Y) is also given as (Y,Fe3+,U)(Nb,Ta)O4.
Tephroite is the manganese endmember of the olivine group of nesosilicate minerals with the formula Mn2SiO4. A solid solution series exists between tephroite and its analogues, the group endmembers fayalite and forsterite. Divalent iron or magnesium may readily replace manganese in the olivine crystal structure.
Adamite is a zinc arsenate hydroxide mineral, Zn2AsO4OH. It is a mineral that typically occurs in the oxidized or weathered zone above zinc ore occurrences. Pure adamite is colorless, but usually it possess yellow color due to Fe compounds admixture. Tints of green also occur and are connected with copper substitutions in the mineral structure. Olivenite is a copper arsenate that is isostructural with adamite and there is considerable substitution between zinc and copper resulting in an intermediate called cuproadamite. Zincolivenite is a recently discovered mineral being an intermediate mineral with formula CuZn(AsO4)(OH). Manganese, cobalt, and nickel also substitute in the structure. An analogous zinc phosphate, tarbuttite, is known.
Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia. Other occurrences include Falun, Sweden where it is found in pegmatites and skarns; and, in the United States, Charlemont, Massachusetts; Spruce Pine, North Carolina; White Picacho district, Arizona; Topsham, Maine; and Franklin, New Jersey.
Tusionite is a rare colorless to transparent to translucent yellow brown trigonal borate mineral with chemical formula: MnSn(BO3)2. The mineral is composed of 18.86% manganese, 40.76% tin, 7.42% boron, and 32.96% oxygen. It is a late stage hydrothermal mineral and occurs rarely in granite pegmatites in miarolitic cavities.
Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word enarge, "distinct". Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45.
Bixbyite is a manganese iron oxide mineral with chemical formula: (Mn,Fe)2O3. The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 – 6.5. It is a somewhat rare mineral sought after by collectors as it typically forms euhedral isometric crystals exhibiting various cubes, octahedra, and dodecahedra.
Sugilite ( SOO-gə-lyte, -jee-) is a relatively rare pink to purple cyclosilicate mineral with the complex chemical formula KNa2(Fe, Mn, Al)2Li3Si12O30. Sugilite crystallizes in the hexagonal system with prismatic crystals. The crystals are rarely found and the form is usually massive. It has a Mohs hardness of 5.5–6.5 and a specific gravity of 2.75–2.80. It is mostly translucent. Sugilite was first described in 1944 by the Japanese petrologist Ken-ichi Sugi (1901–1948) for an occurrence on Iwagi Islet, Japan, where it is found in an aegirine syenite intrusive stock. It is found in a similar environment at Mont Saint-Hilaire, Quebec, Canada. In the Wessels mine in Northern Cape Province of South Africa, sugilite is mined from a strata-bound manganese deposit. It is also reported from Liguria and Tuscany, Italy; New South Wales, Australia and Madhya Pradesh, India.
Cancrinite is a complex carbonate and silicate of sodium, calcium and aluminium with the formula Na6Ca2[(CO3)2|Al6Si6O24]·2H2O. It is classed as a member of the feldspathoid group of minerals; the alkali feldspars that are poor in silica. Yellow, orange, pink, white or even blue, it has a vitreous or pearly luster; a hardness of 5–6 and an uneven conchoidal fracture. It is unusual among the silicate minerals in that it will effervesce with hydrochloric acid due to the associated carbonate ions.
Libethenite is a rare copper phosphate hydroxide mineral. It forms striking, dark green orthorhombic crystals. It was discovered in 1823 in Ľubietová, Slovakia and is named after the German name of that locality (Libethen). Libethenite has also been found in the Miguel Vacas Mine, Conceição, Vila Viçosa, Évora District, Portugal, and in Tier des Carrières, Cahai, Vielsaim, Stavelot Massif, Luxembourg Province, Belgium.
Zabuyelite is the natural mineral form of lithium carbonate, with a formula Li2CO3. It was discovered in 1987 at Lake Zabuye, Tibet, after which it is named. It forms colorless vitreous monoclinic crystals.
Zakharovite is a mineral, a silicate of sodium and manganese; formula Na4Mn5Si10O24(OH)6·6H2O. It has a yellow colour with a pearly lustre. Discovered in 1982 in the Kola peninsula of Northern Russia, it is named after Evgeny Evgenevich Zakharov (1902–1980), the director of the Moscow Institute of Geological Exploration.
Sabinaite (Na4Zr2TiO4(CO3)4) is a rare carbonate mineral. It crystallizes in the monoclinic crystal system as colorless to white prisms within cavities. It is more typically found as powdery coatings and masses. It has a specific gravity of 3.36.
Gunningite is one of the minerals in the Kieserite group, with the chemical formula (Zn,Mn2+)SO4·H2O. Its name honours Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a professor at the University of British Columbia.
Thomasclarkite-(Y) is a rare mineral which was known as UK-93 until 1997, when it was renamed in honour of Thomas H. Clark (1893–1996), McGill University professor. The mineral is one of many rare-earth element minerals from Mont Saint-Hilaire. The only reported occurrence is in an alkalic pegmatite dike in an intrusive gabbro-nepheline syenite.
Brownleeite is a silicide mineral with chemical formula MnSi. It was discovered by researchers of the Johnson Space Center in Houston while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite, Mn5Si3.
Baumhauerite (Pb3As4S9) is a rare lead sulfosalt mineral. It crystallizes in the triclinic system, is gray-black to blue-gray and its lustre is metallic to dull. Baumhauerite has a hardness of 3.
